The invention relates in general to boring tools and more specifically to drill bits for a wide variety of applications but particularly for manufacturing and for finish type boring applications.
As those skilled in the art are aware designs of heretofore known drilling bits have been such that they are unable to withstand the severe conditions to which they are at times subjected. Occasionallya boring tool will strike a nail and become nicked and therefore have to be replaced unless it can be reground. Conventional drill bits, if replaced are expensive and regrinding is also a costly operation. Most of the presently known bits are not made substantially or ruggedly enough to remain sharp but in fact must be sharpened or reground frequently. Additionally, known bits are prone to clog and to therefore jam the drill. Furthermore, conventional drill bits will catch or hang up if they emerge in such a way that part of the hole is finished and part is not. In other words, if the drill is through drilling on one side and not the other, the tendency in conventional bits is to jam. Also, because conventional bits are constructed with a so-called flat or radially extending face, it is difficult to enter the wood at an angle since the outer edges of the bit engage the wood before the lead screw. Furthermore, there is a tendancy to mis-align if the lead screw is not taking hold.
Prior art to be considered will be found in U.S. Pat. Nos. 2,681,673; 2,752,965; 2,812,791; 3,165,131; and 3,687,565. None of the cited patents is thought to be pertinent to the structure of this invention.